1. Field
Example embodiments relate to an organic light emitting diode display device. More particularly, example embodiments relate to a high resolution organic light emitting diode display device, wherein deposition of a light emitting layer for each sub-pixel is easy and precision of patterns of sub-pixels is improved.
2. Description of the Related Art
As organic light emitting diode (OLED) display devices have a wide viewing angle, excellent contrast ratio, and high response speed, they are considered as the next-generation display devices.
An OLED display device may include a first electrode and a second electrode facing each other, and an intermediate layer including at least a light emitting layer between the first and second electrodes. The first electrode, the second electrode, and the intermediate layer may be formed using various methods, such as a deposition method. When the deposition method is used, a mask with opening portions having the same patterns as the patterns of a film to be deposited is used. The mask may be closely adhered to a surface where the film is to be formed, and a material may be deposited on the surface through the mask to form a thin film having predetermined patterns.
When the conventional OLED display device includes a plurality of pixels, e.g., each pixel including red, green and blue sub-pixels, light emitting layers of the sub-pixels may be formed using the deposition method. For example, the light emitting layers of all the sub-pixels emitting red light may be formed by deposition through a mask at the same time, then the light emitting layers of all the sub-pixels emitting blue light may be formed by deposition at the same time, and then the light emitting layers of all the sub-pixels emitting green light may be formed by deposition at the same time.
However, since distances between adjacent sub-pixels become smaller in order to manufacture display devices having high image quality, the distance between the opening portions of a mask for depositing light emitting layers of sub-pixels may be also reduced. For example, if red, green, and blue sub-pixels are repeatedly formed in this order along a first direction, a distance along the first direction between two adjacent opening portions of the mask for the green light emitting layer in quarter common intermediate format (QCIF) OLED having a resolution of 140 ppi may be about 0.068 mm, i.e., a distance along the first direction between two adjacent sub-pixels emitting green light. While a conventional fine pitch mask, e.g., a mask in which the distance between adjacent opening portions is about 0.068 mm, may facilitate manufacturing of an OLED display device having high image quality, there may be many limitations, e.g., physical limits, in manufacturing such a fine pitch mask. In addition, as the pitch of the mask is reduced, it may be difficult to pattern a mask and to align the patterns of the mask with corresponding portions of the OLED display device, i.e., portions where the light emitting layers are to be deposited. Inaccurate alignment and patterning of the mask may cause inaccurate film deposition of the light emitting layers, thereby reducing display properties and image quality of the OLED display device.